A Gaussian year is defined as 365.2568983
day
A day is the time period of a full rotation of the Earth with respect to the Sun. On average, this is 24 hours, 1440 minutes, or 86,400 seconds. In everyday life, the word "day" often refers to a solar day, which is the length between two so ...
s. It was adopted by
Carl Friedrich Gauss
Johann Carl Friedrich Gauss (; german: Gauß ; la, Carolus Fridericus Gauss; 30 April 177723 February 1855) was a German mathematician and physicist who made significant contributions to many fields in mathematics and science. Sometimes refer ...
as the length of the
sidereal year
A sidereal year (, ; ), also called a sidereal orbital period, is the time that Earth or another planetary body takes to orbit the Sun once with respect to the fixed stars.
Hence, for Earth, it is also the time taken for the Sun to return to the ...
in his studies of the dynamics of the solar system.
A slightly different value is now accepted as the length of the sidereal year,
and the value accepted by Gauss is given a special name.
A particle of negligible mass, that orbits a body of 1 solar mass in this period, has a mean axis for its orbit of 1
astronomical unit
The astronomical unit (symbol: au, or or AU) is a unit of length, roughly the distance from Earth to the Sun and approximately equal to or 8.3 light-minutes. The actual distance from Earth to the Sun varies by about 3% as Earth orbits t ...
by definition. The value is derived from
Kepler's third law
In astronomy, Kepler's laws of planetary motion, published by Johannes Kepler between 1609 and 1619, describe the orbits of planets around the Sun. The laws modified the heliocentric theory of Nicolaus Copernicus, replacing its circular orbits ...
as
:
where
:''k'' is the
Gaussian gravitational constant
The Gaussian gravitational constant (symbol ) is a parameter used in the orbital mechanics of the Solar System.
It relates the orbital period to the orbit's semi-major axis and the mass of the orbiting body in Solar masses.
The value of histori ...
.
See also
References
Types of year
Astronomical coordinate systems
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